Such electromechanical transducers are used in measurement and regulating technology, for instance. As an example, devices for ascertaining and/or monitoring a predetermined fill level in a container that have a mechanical oscillation structure, mounted at the level of the predetermined fill level, that is excited into oscillation by an electromechanical transducer are available on the market. One example of such a device is described in German Patent Disclosure DE-A 41 18 793. The oscillations of the mechanical oscillation structure are picked up and converted into electrical signals, which are accessible for further processing and/or evaluation. From the electrical signals, a frequency and/or an amplitude of the oscillation can for instance be determined. The frequency and/or amplitude offer information about whether the mechanical oscillation structure is covered by a product filling the container, or not.
Such fill level limit switches are used in many branches of industry, in particular in chemistry and in the food industry. They serve the purpose of limit state detection and are used for instance to secure against overfilling or to prevent pumps from running empty.
Electronic transducers with piezoelectric elements disposed in a stack offer the advantage that a plurality of piezoelectric elements can be connected electrically parallel and mechanically in series. As a result, a very robust, powerful transducer can be achieved.
In conventional electromechanical transducers, the piezoelectric elements are typically stacked mechanically, and planar electrodes are inserted between each two adjacent piezoelectric elements and secured for instance by means of an adhesive. These electrodes have contact lugs, extended out of the stack, by way of which the piezoelectric elements are to be connected.
Producing such a stack is very labor-intensive. This is very expensive, especially given the high numbers of items typically required.